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(No ModeL) G.M.HOPKINS.

Telegraph Relay.

No. 229,414. Patented June 29,1880.

NTOR:

.is a detail view of a circuit-breaker.

UNITED STATES PATENT OFFICE.

GEORGE M. HOPKINS, OF BROOKLYN, NEW YORK.

TELEGRAPH-RELAY.

SPECIFICATION forming part of Letters Patent N0. 229,414, dated June 29, 1880.

Application filed May 12, 1880.

To all whom it may concern:

Be it known that I, GEORGE M. HorKINs, of Brooklyn, in the countyof Kings and State of New York, have invented a new and useful Improvement in Telegraph'Rel-ays; and I do hereby declare that the following is a full, clear, and exact description thereof, reference being made to the annexed drawings, making a part of this specification, in which Figure 1 is a transverse section of my improved relay. Fig. 2 is a plan view. Fig. 3 Fig. 4 is a modification of the circuit-breaker shown in Fig. 3.

My invention relates to relays for telegraphic and analogous purposes; and it consists, essentially, in an expansion rod, wire, or body, forming a portion of the main-line circuit, and

capable of offering sufficient resistance to the more feet long.

passage of the electric current to become slightly heated and correspondingly expanded.

This expansion of the wire or rod I utilize in operating a local-circuit breaker which controls a local sounder. The expansion of the wire is not. always uniform. Neither will it contract as readily as it will expand.

One of the main objects of my invention is to render the irregular movements of the mechanism connected with the expansion-wire available in controlling a local circuit.

Referring to the drawings, A is an expansion-wire, which may be of any of the metals expansible by heat, by magnetism, or by the passage of an electric current. A fine brass wire is preferable, as it readily expands and contracts quicker than wires made from other metals; but I do not confine myself to brass, nor entirely to metals, as I may use any substance which is elongatcd or contracted by the passage of an electric current or by the influence of magnetism.

The wire A may be from one to three or It is connected with an adjusting-screw, a, at one end, and the other end is connected with a piece of metal, I), jointed to the shorter arm of a lever, B. The post containing the adjusting-screw a serves also as a binding-post for receiving one end, 0, of the main-line wire.

The lever B in the present case is made of insulating material, and the expansion-wire A (No'model) is connected with the end of the main-line wire by means of the coiled wire 0, which allows the lever B to move freely. The contraction of the wire A is opposed by a spring, f, which is connected with the lever B and with a post, f, and always keeps the wire taut. The lever B is pivoted on the pintle K, so that it may be pressed downward by the spring f A pivot, g, projects from the end of the longer arm of the lever B, and upon it is placed a notched roller, 0, of vulcanite or other suitable material, carrying a platinum contact-surface, h, which is capable of touching a platinum contact-point, t', supported by the arm B. The surface It is in electrical communication with the pivot g, and the pivot g is connected by a wire, g, with the pintle K of the lever B through the springf and the piutle K turns in a screw, 1, which is connected with a bindin g-post, m, by suitable conductor. The platinum point t is connected by a wire, at, with the hook it, which receives the spring f, and the spring f is in electrical communication with the binding-post 0. The binding-posts m 0 are for the purpose of receiving the localcircuit wires.

When an electrical current is sent through the main line the expansion-wire A expands more or less, according to its length and the strength of the current passing through it. The expansion of the wire allows the spring f to move the lever B more or less, and as the roller 0 touches the friction-surface p it is turned on its pivot so as to bring the surface It into contact with the pointi completin g the local circuit. Wile 11 the main-line circuit is open the contraction of the wire A follows, and .the slightest motion of the roller O in the opposite direction breaks the local circuit.

The operation just described takes place no matter what angle the lever B forms with the expansiouwire A, and it makes no difference how great or how slight the motion of the lever B may be, the local circuit is established or broken in unison with the motion of the transmitting-key.

Instead of employing the friction-surface p I may use a liquid resisting medium, and suspend from the roller O a paddle, q, to be acted on by the resistance of the medium, as shown in Fig. 4.

By making a movable anvil for the lever B to strike against, the device may be used for a main-line sounder, and the Wire A may be compounded by the use of additional levers.

The advantages of this relay over the ordinary forms having great resistance consist, first, in the removal from the main line of an enormous resistance, and a consequent reduction in the amount of battery-power required; second, in the reduction in the cost of relays, simplifying them by substituting a short piece of Wire for a number of miles usually contained in a relay.

Having thus described my invention, What I claim as new,and desire to secure by Letters Patent, is-

l. The method of operating a local telegraphic circuit by the expansion and contraction of an electrical conductor forming a part of the line, substantially as specified.

2. In a telegraph-relay, the expansion-wire A, lever B, friction-roller O, and the local-circuit contact-surfaces h i, in combination, as specified.

GEORGE M. HOPKINS.

Witnesses H. M. HOPKINS, O. SEDGWICK. 

